• Title/Summary/Keyword: construction control

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A Study on Traffic Accident Characteristics of Freeway Work Zones (고속도로 공사구간에서 발생하는 교통사고 특성에 관한 연구)

  • Park, Tae-Hoon;Park, Je-Jin;Yoon, Pan
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.7 no.1
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    • pp.127-136
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    • 2008
  • In these days, frequency of constructions on e freeway are increasing according as growing of the importance of e road maintenance and the road management. Work zone on the freeway where vehicles pass with high speed needs control method of lane closure and construction equipment. Because there are seldom researches in domestic study about reflecting characteristics of domestic road, sometimes we have applied for foreign cases to our traffic circumstance but it is not proper to apply for standard of other countries in our cases. foreign nation has different country square, condition of road, and level of people mind. Therefore, this study shows traffic accident characteristics in freeway work zones in Korea. At first, this study collected traffic accident data which include for 3 years $2003{\sim}2005$ in the whole freeway in Korea and then divided the data to five parts - level of the accident, type of the construction work, type of the accident, reason of the accident, according to geometric. According to comparing with non-work zones accident, this study found traffic accident characteristics in freeway work zones in Korea and suggested some alternative ideas for safety of work zones.

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Proposals of Integration of Korea Industrial Standard for Aggregates for Efficient Quality Control of Concrete Aggregate (콘크리트용 골재 품질 관리 효율화를 위한 골재 관련 KS 표준 통합 방안)

  • Lee, Jun-Seok;Han, Min-Cheol
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.4 no.2
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    • pp.125-135
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    • 2016
  • The objective of this paper is to provide integrated Korea industrial standards(KS) for concrete aggregates, which has been separately provided with ten kinds of KS, in order to improve the way of quality management of concrete aggregate and to prevent distribution of unsuitable aggregates. For the sequences of the paper, typical foreign standards related to concrete aggregates including ASTM for US, EN for EU, JIS for Japan are reviewed and compared to provide necessities and feasibilities of the paper. Based on the analysis above results, existing KS for concrete aggregates, which have been separately provided with ten kinds being lack of correlation between each KS is integrated to KS F 2526 "Aggregates for concrete" in this paper. By doing this, in terms of terminology, the expression of the aggregate, which has been currently classified into specified terminologies of aggregates depending on sources, manufacturing methods of each aggregates, is able to be integrated to single expression of the aggregate for concrete. It is believed that integrated KS presented herein provides more desirable way in terms of its better accessibility, easier revision and closer connection between each aggregate kinds.

Influence of Painting Materials based on Wasted Oil and Applying Timing on Carbonation and Chloride Resistances of High Volume SCM Concrete (폐유지류를 중심으로 한 도포제 종류 및 도포시기 변화가 혼화재 다량치환 콘크리트의 탄산화 및 염해저항성에 미치는 영향)

  • Han, Cheon-Goo;Choi, Young-Doo
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.3 no.3
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    • pp.228-236
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    • 2015
  • In this research, the influence of painting materials and applying timing on carbonation and chloride resistances of high volume SCMs concrete was evaluated. As a durability improving method, comparative tests were conducted with painting materials of ERCO (emulsified refined cooking oil), RCO (refined cooking oil), WR (water repellent agent), and ERCO + WR and with painting timings of right after demolding, and 28 days after the wet curing. From the experiment results, in the case of carbonation and chloride resistance, the carbonation depth and chloride penetration depth were decreased when the painting materials were applied in 28 days of wet curing. Additionally, for painting materials, with the order of ERCO, RCO, ERCO+WR, and WR, the carbonation and chloride penentration was delayed. Hence it is considered that ERCO shows the most favorable performance of resistance against carbonation and chloride penetration.

Analytical Estimation of the Performance of Marine Concrete with Mineral Admixture (광물질 혼화재를 혼합한 해양 콘크리트의 해석적 성능 평가)

  • Lee, Bang-Yeon;Kwon, Seung-Jun;Kang, Su-Tae
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.3 no.4
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    • pp.301-306
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    • 2015
  • For the purpose of developing high performance marine concrete with improved crack resistance and durability, this analytical study aimed to estimate strength, hydration heat characteristics, and chloride attack resistance of concrete with mineral admixture. Ground granulated furnace slag and fly ash were considered for mineral admixture. The replacement of ground granulated furnace slag and fly ash considered in the analysis was in the range of 0~70% and 0~40 %, respectively. The analysis results indicated that both ground granulated furnace slag and fly ash decreased compressive strength, and the effect of adding ground granulated furnace slag on mitigation of hydration heat was limited whereas fly ash had an noticeable influence on it. It was also found that the replacement with ground granulated furnace slag enhanced the chloride attack resistance but fly ash deteriorated the resistance. From the analytical studies, It could be expected that a ternary blended cement composition with proper amount of ground granulated furnace slag and fly ash might be effective to control crack resistance as well as chloride attack resistance of marine concrete.

Crack Control of the Upside of Double Tee Slab and Inversed Tee Beam Joint (더블티 슬래브-역티형 보 접합부 상부의 균열억제를 위한 실험연구)

  • Nam, Sang-Uk;Song, Han-Beom;Yi, Waon-Ho;Yang, Won-Jik;Baik, Young-Soo;Tae, Kyung-Hoon
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.04a
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    • pp.345-348
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    • 2008
  • Recently, demand is caused that new building environment of value added rising demand on the lines of becoming bigger, manhattanize of structure and becoming high standard of structure in a construction site and influx of advanced foreign nation technique. To satisfy these requirements for alternative, structures applied to the PSC, PC is increasing. Double Tee Slab is possible for long length structure and applied to the method of construction. When assembling Double Tee Slab produced by the factory in the field, becamed carry-out topping concrete in upper, but occurred crack to slab line. There is no structural problem to crack occurred in upper, waterproof in maintenance and repair of structure due to a conservative cause several problems.

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Characteristics of Diffusion Coefficient of High Performance Concrete using GGBFS for Road Structures by Accelerating Test Method (슬래그 미분말 혼입률에 따른 도로구조물용 고성능 콘크리트의 압축강도 및 촉진 염소이온 확산 특성)

  • Han, Seong-Woo;Kim, Hong-Sam;Lee, Chan-Young;Cheong, Hai-Moon;Ahn, Tae-Song
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.04a
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    • pp.885-888
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    • 2008
  • In recent years, the terminology "High-Performance Concrete(HPC)" has been introduced into the construction industry. Most high-performance concretes have a high cementitious content and a low water-cementitious material ratio. The proportions of the individual constituents vary depending on local preferences and local materials. Therefore, many trial batches are usually necessary before a successful mix is developed. The objective of this experiments is to investigate the fundamental properties of high performance concrete based binary cimentitious materials such as ordinary portland cement and ground granulated blast furnace slag. The results from the study will be utilized as the basic data and guideline in making standard mixproportions and the manufacture, construction work and quality control of HPC

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Evaluation of Influence Factors in order to introduce Share-styled Apartment House Successfully (지분형 주택분양제도의 성공적인 도입을 위한 영향요인 분석)

  • Lee, Hyun-Chul;Lim, So-Yean;Go, Seong-Seok
    • Korean Journal of Construction Engineering and Management
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    • v.11 no.1
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    • pp.79-87
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    • 2010
  • The purpose of this study is to find decisive factors affecting Share-styled Apartment house Lee Myung-bak announced for the homeless masses in February 2008. This policy tried to add up defects from Half-priced Apartment house enforced in 2007. Seoul is ranked as the highest PIR(Price Income Rate) city in the world, as far as the difficulties in getting own house is concerned. Korean government has announced a lot of policies to control the price of real-estate, especially housing bubble phenomenon, since the convalescence from IMF financial crisis. By making questionnaires to get an important factor and taking counsel with related specialists, this thesis found what kind of roles the objects including government, institutions and people should play or focus on.

Construction Method of Time-dependent Origin-Destination Traffic Flow for Expressway Corridor Using Individual Real Trip Data (실제 통행기록 자료를 활용한 고속도로 Corridor 시간대별 O-D 구축)

  • Yu, Jeong Whon;Lee, Mu Young
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.31 no.2D
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    • pp.185-192
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    • 2011
  • More practical outputs and insights can be obtained through transportation analysis considering the time-dependent traffic movements. This study proposes a method of constructing time-dependent O-D trip tables for expressway corridor using real-world individual trip data. In this study, time-dependent O-D trip tables for the nationwide highway network are constructed based on toll collection system data. The proposed methodology is to convert nationwide time-dependent O-D trip tables into Korean expressway corridor O-D trip tables in order to deal with the computational complexity arising from simulating a large-scale traffic network. The experiment results suggest that actual individual trip record data can be used to effectively construct time-dependent O-D trip tables. They also imply that the construction of time-dependent O-D trip tables for the national highway networks along with those for Korean expressway developed in this study would make transportation analysis more practical and applicable to real-time traffic operation and control.

Evaluation of Liquid Droplet Impingement Erosion through Prediction Model and Experiment (예측모델 및 실험을 통한 액적충돌침식 손상 평가)

  • Yun, Hun;Hwang, Kyeong-Mo
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.35 no.10
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    • pp.1105-1110
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    • 2011
  • Flow-accelerated corrosion (FAC) is a well-known phenomenon that may occur in piping and components. Most nuclear power plants have carbon-steel-pipe wall-thinning management programs in place to control FAC. However, various other erosion mechanisms may also occur in carbon-steel piping. The most common forms of erosion encountered (cavitation, flashing, Liquid Droplet Impingement Erosion (LDIE), and Solid Particle Erosion (SPE)), have caused wall thinning, leaks, and ruptures, and have resulted in unplanned shutdowns in utilities. In particular, the damage caused by LDIE is difficult to predict, and there has been no effort to protect piping from erosive damage. This paper presents an evaluation method for LDIE. It also includes the calculation results from prediction models, a review of the experimental results, and a comparison between the UT data in the damaged components and the results of the calculations and experiments.

A Schemes of Improving about Accrual Basis Accounts and Bookkeeping by Double Entry for Financial Transparency of Local Governments (지방자치단체 재정관리 투명성 확보를 위한 발생주의·복식부기회계 개선방안 탐구)

  • Choi, Rackin
    • Journal of the Korea Society of Computer and Information
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    • v.18 no.1
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    • pp.157-166
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    • 2013
  • This study searches a transparency of financial management of Local government and then, tries to find a solutions to a management scheme to strengthen financial reform effectively. To summarize main contents: First, requirement of continued Public Accounting System. Second, contact of items of an account and items of a program budget, Third, requirement of construction cost accounting to estimate total cost inputting to public program objectively. Forth, improvement of rotation assign system and guaranteeing to professionalism and public official ethics. Fifth, requirement of strengthening inter-control and monitoring system. Sixth, auditing and role of accounting specialist group. Finally, construction of effective and practical computer system and continuing practice of R&D program.